Impact of Acid (Progressive Brush) and Alkaline Straightening on the Hair Fiber: Differential Effects on the Cuticle and Cortex Properties
January 2022
in “
International journal of trichology
”
TLDR Glyoxylic acid straighteners cause more protein loss but have similar hair strength effects as traditional alkaline straighteners.
This study compared the effects of glyoxylic acid and traditional alkaline straighteners (sodium hydroxide, guanidine hydroxide, and ammonium thioglycolate) on hair fibers. Glyoxylic acid caused the most protein loss (3.5 μg/g) compared to untreated hair (1.12 μg/g) and other straighteners (2.5 μg/g). Despite this, the tensile strength of hair treated with glyoxylic acid was similar to that treated with alkaline straighteners. The study suggests that glyoxylic acid alters disulfide bridges rather than breaking and rearranging them, affecting hair strength. Application technique, reaction time, and reapplication intervals are also crucial factors influencing the results.
